   Bots that run into item spaces that cannot be occupied will receive damage. If the item that is
   collided with has energy, it to will receive damage. If the item collided with has an energy level
   of 0 or less after the collision, that item will disappear and the bot will occupy its space."
-  [player-id collision-item collision-coords]
+  [player-id player-coords collision-item collision-coords]
   (fn [{:keys [players dirty-arena] :as game-state}]
     (if (is-player? collision-item)
-      (let [])
+      (let []
+        ;; TODO https://github.com/willowtreeapps/battlebots/issues/57
+        game-state)
       (let [player (get-player player-id players)
             updated-player (apply-damage player collision-damage-amount false)
             updated-players (update-player-with player-id players updated-player)

      (reduce #(%2 %1) game-state [(clear-space player-coords)
                                   (player-occupy-space desired-coords player-id)])
      (reduce #(%2 %1) game-state [(apply-collision-damage player-id
                                                           desired-space-contents
                                                           desired-coords)]))))



(defn- total-rounds
  "Calculates the total number of rounds that have elapsed"
  [num-rounds num-segments]
  (+ (* num-segments segment-length) num-rounds))

(defn- get-player
  "Grabs a player by id from the private player collection"
